Range hood cleaning assembly

ABSTRACT

A range hood cleaning assembly utilizes compressed air to drive accumulated grease on range hood surfaces towards drainage holes. A plurality of air dispensers, preferably air hoses and directional nozzles, through which compressed air from at least one source of compressed air is blown, direct compressed air against surfaces within a motor housing interior, on the fan(s) and within grease trays to drive accumulated grease towards drainage holes. The air dispensers may be attached to a plate mounted within the motor housing interior about a motor and above a fan, may be integral or releasably attachable to the motor housing or may be integral or releasably attachable to grease trays. The compressor may be set to activate automatically or may be activated manually.

FIELD OF THE INVENTION

This invention relates to range hoods, and more particularly to acleaning assembly for a range hood wherein compressed air directsaccumulated grease accumulated within the range hood to an externalgrease receptacle.

BACKGROUND OF THE INVENTION

Range hoods are used above cooking surfaces to remove grease, commonodors and hazardous gases created during the cooking process. Typically,range hoods have a pair of motors horizontally installed in a motorhousing within the hood body. Each motor drives a fan. The fans suck airfrom the cooking area below and force it through the motor housing toventilation piping.

As the vaporized grease contained in the entrained air travels throughthe motor housing, some of it condenses on the inside walls of thehousing from where the shaping of the walls and floor of the housingdirects the grease to a circular grease catcher mounted below each fanopening. Grease catchers are known in the art as illustrated in U.S.Pat. Nos. 6,216,686 B1 and 5,537,988.

Grease catchers are also adapted to capture any grease that drips offthe fan blades when the motors are turned off. Typically, the greasecatcher has radial inner and outer trays with a wall separating them.The wall extends vertically so as to be almost flush with the lower edgeof the outer circumference of the fan. In this way air being drawn in bythe fans is compelled to enter the motor housing rather than the hoodbody. The wall therefore acts to control the air currents of the rangehood.

The grease catchers are usually provided with an inclined base or floor,so as to direct accumulated grease to a hole in the floor. A hose isattached to the hole to convey the grease to a grease receptacle outsidethe range hood.

The motor housing and grease catchers are mounted within the hood body.Openings in the lower surface of the hood body are positioned so as tomatch those of the motor housing. Typically the lower surface of thehood body is removably fitted into the main hood body. A protectivegrill is attached to the outside of each opening in the hood body so asto prevent the insertion of body parts when the fan is in operation.

Alternatively, as set out in my U.S. and Canadian patent applications,numbers 10/035,116 and 2,365,790 respectively, the motor housing may beadapted to act as a grease catcher itself. In this system, a circularwall defining the motor housing intake openings projects vertically intothe motor housing, acting as a barrier to grease accumulated therein.The accumulated grease drains directly from the housing rather than to agrease catcher. Grease trays inserted into the intake openings provide abarrier for proper airflow into the housing and to capture any greasethat should happen to drip from the fan when it has stopped motion.

Both of the foregoing designs rely on gravity to cause the accumulatedgrease to drain out of the range hood. However, gravity is not effectivein removing all the grease with the result that some becomes caked on tothe interior surfaces, thereby reducing the efficiency of the range hoodand creating a possible fire hazard.

The foregoing systems of motor housing and grease catchers thereforerequire periodic cleaning to remove condensed grease accumulated on thefans, motor housing interior and grease trays. In order to clean theinterior of the range hood, a user must first remove the lower surfaceof the hood body, following which the grease catcher must then beremoved. This can be quite awkward and is difficult for those withoutthe strength to support the weight of the lower surface. Washing theinside of the motor housing, the fans and the grease trays to remove theaccumulated grease is also time consuming.

Attempts have been made to overcome the necessity to manually clean theinterior of a range hood exhaust system. It is known in the art toprovide a washing fluid under pressure in order to clean the interior ofthe exhaust system. For example, U.S. Pat. No. 4,259,945 teaches anexhaust system in which a washing fluid under pressure is used to cleanthe flue and fan. Similar washing fluid systems are taught in U.S. Pat.Nos. 3,795,181 and 4,085,735.

A similar approach is known in the art with respect to the range hooddesign described above. A fluid delivering nozzle is fitted into a holein the side of the motor housing so as to deliver a spray of washingfluid to clean the interior. This is done while the motors are activatedso that the force of the air being drawn into the motor housing forcesthe sprayed fluid against the interior surfaces of the motor housing andprevents any liquid from passing through the air intakes.

While these prior art systems reduce the amount of cleaning required ofthe exhaust system, maintenance is still required. Because there is somuch waste fluid resulting from the combination of the grease and thewashing solution, a large waste fluid receptacle is required and must beemptied often. The waste receptacle takes up usable space below therange hood and is not pleasing to the eye. In addition, the washingfluid receptacle must be constantly refilled.

It is therefore an object of an embodiment of the present invention toprovide a range hood in which the interior of the range hood, includingthe motor housing and the fans, may be automatically cleaned without theuse of washing fluid so as to negate the need for a large waste fluidreceptacle or the constant refilling of a washing fluid receptacle.

Various aspects of the invention address these objects, but not allaspects of the invention necessarily address all such objectssimultaneously. Other objects of the invention will be apparent from thedescription that follows.

SUMMARY OF THE INVENTION

The invention is directed to a cleaning assembly for use in a rangehood. According to one aspect of the invention, a plurality of airdispensers are used to direct compressed air against the grease ladensurfaces of the range hood including the fan(s), the interior surfacesof the motor housing and, if applicable, the grease tray(s), therebydirecting any accumulated grease out of the range hood.

In the preferred embodiment, the range hood has a motor housing encasingtwo motors, each motor contained within a separate chamber of the motorhousing and driving a respective fan. At least one source of compressedair, such as an air compressor, acts to drive compressed air through airdispensers, the compressed air acting to force accumulated grease out ofthe range hood.

Preferably, the air dispensers will comprise air hoses with directionalnozzles, however any suitable means of delivering compressed air issatisfactory; for example, hollow, rigid tubes or conduits.

Preferably, a plate is attached about the base of each motor, such thata portion of each of the motors is bordered by a plate. A space ispresent between the plate and the upper surface of the motor housing. Aplurality of air dispensers is attached to each plate and is positionedbetween the plate surface and the upper surface of the motor housing.Compressed air is directed through each air dispenser such that it isdirected against the upper surface of the motor housing. The airdispensers dispense the compressed air over a wide angle. In thepreferred embodiment, four hoses and nozzles are attached to the plate.However, this number can be varied to provide different levels ofcleaning efficiency. While it is preferred that the plate be circular,it need only be shaped so as to fit around the motor and to provide asurface upon which to mount the air dispensers and could for example bestar-shaped or scalloped.

The compressed air forced against the upper surface of the motor housingdrives any accumulated grease down the side of the interior to the lowersurface of the motor housing where it drains to an outer greasereceptacle.

In the preferred embodiment, intake openings in the lower surface of thehousing are formed by walls that project into the interior of the motorhousing (one for each chamber). An extension extends from the wall intothe opening and in a downward direction so as to form a gap between theextension and the wall. The housing is shaped so as to direct anyaccumulated liquid or debris within the housing, such as grease, towardsa drainage hole in the lower surface of the housing where the liquid isdirected out of the range hood. An additional air dispenser is mountedin the side of the motor housing and acts to force liquid accumulated onthe lower surface of the motor housing towards the drainage hole. Theintake opening walls prevent any liquid from passing back through theintake opening.

Two further air dispensers are attached to the underside of the lowersurface of the motor housing, one travelling towards each of the intakeopenings. These air dispensers direct compressed air travelling throughthem towards the blades of the fan mounted above each respective intakeopening.

In one aspect the cleaning assembly is for use in a range hoodcomprising a motor housing having an interior defined by upper, lowerand side surfaces containing at least one motor and at least one fan andhaving at least one drain hole. The cleaning assembly comprises at leastone source of compressed air located externally to the motor housing anda plurality of air dispensers for delivering the compressed air to themotor housing interior.

In another aspect, the air dispensers direct the compressed air againstat least one of the interior surfaces of the motor housing.

In another aspect the cleaning assembly further comprises a platereleasably attachable to the motor housing about the motor and above anupper surface of the fan such that there is a space between the plateand the motor housing.

In another aspect at least a first one of the air dispensers is mountedto the plate in the space.

In another aspect the air dispensers direct compressed air from thesource of compressed air against the upper surface of the motor housinginterior.

In another aspect a second one of the plurality of air dispensers isreleasably attachable to the lower surface of the motor housing anddirects compressed air from the source of compressed air against the atleast one fan.

In another aspect at least a third one of said plurality of airdispensers is integral with the side of the motor housing, the third oneof the air dispensers being positioned within the motor housing interiorabove a top side of the lower surface of the motor housing.

In another aspect the third one of the air dispensers directs compressedair from the source of compressed air against the top side of the lowersurface of the motor housing.

In yet a further aspect the cleaning assembly according to the inventionis for use in a range hood comprising a motor housing having an interiordefined by upper, lower and side surfaces containing at least one motorand at least one fan, and a grease tray. The grease tray is releasablyattachable to the motor housing and comprises an opening, first, secondand third tray walls extending around the opening, a first trough formedbetween the first and second tray walls, a second trough formed betweenthe second and third tray walls, and at least one drainage hole. Thecleaning assembly comprises at least one source of compressed airlocated externally to the motor housing and a plurality of airdispensers for delivering the compressed air to the interior.

In another aspect a first of the plurality of air dispensers is integralwith the first, second and third tray walls.

In another aspect the first of the air dispensers directs compressed airfrom the source of compressed air against the at least one fan.

In another aspect at least a second one of the plurality of airdispensers is integral with the first tray wall, the second one of theair dispensers directing compressed air from the source of compressedair into the first trough.

In yet a further aspect the invention comprises range hood cleaningassembly wherein the range hood has a motor housing having upper, lowerand side surfaces that generally defines an enclosure containing atleast one motor and at least one fan. The lower surface has at least oneintake opening and at least one drain hole. A wall depending from thelower surface and projecting into the interior of the enclosure definesthe intake opening. A tray is releasably connectable to the intakeopening. The tray comprises an opening, first and second tray wallsextending around the opening, and a floor between the first and secondtray walls. The cleaning assembly comprises at least one source ofcompressed air located externally to the motor housing and a pluralityof air dispensers for delivering the compressed air within the rangehood.

In another aspect a second one of said plurality of air dispensers isreleasably attachable to the lower surface of the motor housing. Thesecond one of the air dispensers directs compressed air from the sourceof compressed air against the at least one fan. The first and secondtray walls have a gap in which the second one of the air dispensers maybe fitted when the tray is releasably connected to the intake opening.

In another aspect a second of said plurality of air dispensers isreleasably attachable to the tray, the second air dispensers directingcompressed air from the source of compressed air against the at leastone fan when the tray is releasably connected to the intake opening.

In another aspect the air dispensers comprise air hoses and nozzles,each air hose having a first end connectable to the source of compressedair and a second end releasably connectable with a respective one of thenozzles.

In yet a further aspect the invention comprises a cleaning assembly foruse in a range hood comprising a motor housing having an interiordefined by upper, lower and side surfaces containing at least one motorand at least one fan and having at least one drain hole. The cleaningassembly comprises at least one source of compressed air, a plurality ofair hoses wherein each of the plurality of air hoses having a first andsecond end, a plurality of nozzles wherein at least one nozzle isreleasably connected to each of the first ends and each of the secondends are releasably connected to the source of compressed air.

In yet another aspect the nozzles direct compressed air from the sourceof compressed air against at least one of the interior surfaces of themotor housing whereby to dislodge grease and debris from the at leastone interior surfaces.

Other aspects of the invention will be appreciated by reference to thedetailed description of the preferred embodiment and to the claims thatfollow.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by reference to the detailed descriptionof the preferred embodiment and to the drawings thereof in which:

FIG. 1 is a sectional view of a range hood according to the preferredembodiment of the invention with the right hand portion of the figureproviding a deeper sectional view than the left hand portion of thefigure;

FIG. 2 is a view taken along line 2-2 of FIG. 1;

FIG. 3 is an exploded sectional view of portions of the range hood ofFIG. 1;

FIG. 4 is a sectional view of a range hood according to an alternativeembodiment of the invention with the right hand portion of the figureproviding a deeper sectional view than the left hand portion of thefigure;

FIG. 5 is an exploded sectional view of portions of the range hood ofFIG. 4;

FIG. 6 is a sectional view of a further alternative embodiment of arange hood according to the invention with the right hand portion of thefigure providing a deeper sectional view than the left hand portion ofthe figure;

FIG. 7 is a plan view of the grease tray of the range hood of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to a cleaning assembly for a range hood.

The cleaning assembly is composed of a source of compressed air such asa compressor and air dispensers for directing the compressed air againstgrease coated surfaces within the range hood. The compressed air is usedto drive accumulated grease out of the range hood. This will bedescribed in greater detail below by reference to the preferred andalternative embodiments.

The preferred embodiment of a range hood 100 with a cleaning assemblyaccording to the invention is illustrated in FIG. 1. In the preferredembodiment, the motor housing 110 includes an integral grease catcher.The housing 110 defines an enclosure and is mountable within a furtherenclosure formed by the hood body generally indicated by the numeral102. The interior of the housing 110 is coated with a non-stick materialso as to facilitate grease removal and is separated into twosubstantially similar, separate chambers 2, 4 as best illustrated inFIG. 2. The chambers 2, 4 have intake openings 112 shown in FIG. 3, andventilation holes (not shown). The ventilation holes project through theupper surface of hood body 102 when the housing 110 is attached to theinterior of the hood body 102.

Two motors 125 fit within the motor housing 110 and are attached to theinside of the upper surface of the hood body 102, one in each ofchambers 2 and 4. Fans 120, of the semi-impeller type, one secured toeach of the motors 125 by fan caps 129, act to draw grease-laden airinto the motor housing 110 and out the ventilation holes. A plate,preferably shaped as a circular disc 8 is attached about the base ofeach of the motors 125 such that there is a space between plate 8 andthe upper surface of the interior of motor housing 110. Preferably, theplate 8 has a maximum radius that is approximately equal to the maximumradius of the fans 120, the plates 8 being positioned just above theupper surface of the fans when they are installed in the motor housing110. The plate acts to prevent the air dispensers from coming intocontact with any moving parts, such as the fans 120, within the motorhousing. The fans 120 and plate 8 are dimensioned so as to be removablefrom within the housing 110 through openings 112.

The motors 125 are positioned within the motor housing so that when thefans 120 are attached they are positioned above intake openings 112 (ofthe motor housing 110) and air inlets 109 (of the lower panel 108), bestshown in FIG. 3. The design of the motor housing 110 is such that whenthe fan is in position, the distance between the fan and the side wallof the motor housing increases in the direction of rotation of the fan,the space being the largest in the area of the ventilation holes,thereby maximizing air flow. This is best illustrated in FIG. 2. In thepreferred embodiment the fans are counter-rotating as indicated byarrows 6, 7 in FIG. 2. However, the cleaning assembly is designed towork with alternative configurations such as where the fans rotate inthe same direction.

As shown in FIG. 3, openings 112 in motor housing 110 have walls 130depending and rising vertically from the lower surface of the motorhousing. An outwardly and downwardly projecting extension or lip 132depends from wall 130, so as to form a gap 134 between the lip 132 andwall 130. Extension 132 may diverge from wall 130 such that gap 134forms a wedge surface. A tray 140 is dimensioned such that its outerwall 142 may be releasably connected to gap 134. This is discussed ingreater detail below.

The lower surfaces of the chambers 2, 4 of the motor housing 110 areeach shaped such that any accumulated grease or other condensed liquid(condensate) is directed by gravity towards the respective drain holes123, 124 (see FIGS. 1, 2). Holes 123, 124 are therefore located at thelowest point of lower surface 118 of the motor housing. As seen in FIG.3, drainage hoses 127, 128 are attached to each of holes 123 and 124.Accumulated condensate travels through drainage hoses 127, 128 by way ofgravity to external grease cups 126 (only one of which is shown in FIG.1).

Wall 130 acts as a barrier to any condensate which accumulates in theinterior of the motor housing, preventing it from dripping throughopenings 112.

Using chamber 2 as an example, air dispensers of the cleaning assembly,preferably four air hoses 12, 14, 16 and 18 are attached to the uppersurface of plate 8 as shown in FIGS. 1, 2 and 3. This configuration ismirrored in chamber 4. Depending on the size of the range hood and thedispersion characteristics of the air hoses and nozzles, less than ormore than four air hoses could be used. At the end of each of air hoses12, 14, 16 and 18 is a nozzle 20. The nozzles 20 are approximatelyequally spaced about the outer circumference of, and firmly attached toplate 8. The air hoses 12, 14, 16 and 18 pass through a hole in themotor housing and are attached to at least one air compressor (notshown). Preferably the hoses 12, 14, 16 and 18 are collected withinrubber covering 24 as shown in FIG. 2, however this need not be thecase. It is also contemplated that air hoses 12, 14, 16 and 18 couldconnect to a larger hose by way of a multi ended adapter or simply passthrough the wall of the motor housing individually provided solely thateach hose is connected at one end to a compressor and at the other endto a nozzle 20. A plastic or rubber gasket seal (not shown) similar tothat employed with respect to the power cord 50 of the motor 125 may beused to prevent any air from escaping from the motor housing where theair dispensers pass through, however anything preventing air frompassing through is satisfactory. It is also contemplated that the airhoses 12, 14, 16 and 18 could be combined with the power cord 50 suchthat they pass through the motor housing wall together.

When in operation, compressed air travels through air hoses 12, 14, 16and 18 to nozzles 20, which widely disperse compressed air from the aircompressor radially outward against the upper surface of the motorhousing. This compressed air then follows the contours of the interiorof the housing chambers, such that accumulated condensate in eachchamber is directed from the upper surface and down the sides towardsthe lower surface 118 where it is prevented from passing back throughopenings 112 by walls 130 in troughs 150 formed between wall 130 and theside wall of the motor housing.

Further air dispensers act to direct grease along the bottom surfacetowards the drainage holes 123, 124. This is accomplished by way ofintegrated nozzles 42, 44 in the motor housing 110 to which air hoses26, 28 may be releasably attached as shown in FIG. 2. Air hoses 26, 28are also attached to a source of compressed air such as an aircompressor. While only one integrated nozzle 42 or 44 is shown in eachof chambers 2 and 4, it is contemplated that further integrated nozzlescould be spaced about the perimeter of the motor housing should greatergrease dispersing power be required. Integrated nozzles 42, 44 arepositioned within troughs 150 so as to direct a wide spray of compressedair against the lower surface of the motor housing in the respectivedirection of rotation 6, 7. Air follows troughs 150 forcing condensatearound the perimeter of walls 130 towards drainage holes 123, 124.Condensate entering the drainage holes 123, 124 travels to externalgrease cups 126 by way of drainage hoses 127, 128.

As illustrated in FIGS. 1, 2 and 3, for each compartment the aircleaning assembly also includes a further air hose 162 connected at oneend to nozzle 160 and at the other end to an air compressor. The nozzle160 is positioned so as to direct compressed air from the air compressoragainst the fans 120 so as to force grease accumulated on the fans 120into the compartments 2, 4. The nozzle 160 is releasably connectable tothe bottom of the motor housing. In this way, it can be disconnected inorder to allow the fan, motor or plate to be removed from the interiorof the motor housing. Once connected to the motor housing, hose 162 maybe releasably attached to the nozzle by way of clip 290 or other means.

The tray 140 while also being releasably connectable to housing 110,also connects to the lower panel 108, which is removable from theremainder of main hood body 102. Lower panel 108 has a pair of airinlets 109, one of which is shown in FIG. 3. Air inlets 109 are definedby circular vertical walls 101, which depend, and rise vertically from,lower surface 108. The circular vertical walls 101 can vary in heightbetween a minimum height and a maximum height. The minimum height is theheight at which the circular vertical walls 101 will remain in contactwith the tray 140 when it is connected to the housing 110 as describedbelow. The maximum height is the height at which the top of the circularvertical walls 101 abuts the bottom of the nozzle 160 when the lowerpanel 108 is connected with hood body 102.

Tray 140 is connected to the range hood 100 by inserting it throughintake opening 109 in lower panel 108 and into intake opening 112 in themotor housing 110 until outer wall 142 is firmly in place within gap134. Tray 140 may be releasably connected to housing 110 by wedgingouter wall 142 into gap 134. When connecting the tray 140, it must bepositioned so as to line-up gap 148 (shown in FIG. 3) with nozzle 162such that the nozzle is positioned tightly within the gap 148. When tray140 is connected to the housing 110, outer wall 142 is also in contactwith lower panel 108 and acts to seal any space that may exist betweenthe housing and the lower panel thereby preventing air from enteringinto any undesired area within the range hood body 102. A clip or otherform of suitable restraint (not shown) accessible on the outside surfaceof the range hood is used to hold the tray in place. In this way, lowerpanel 108 need not be removed in order to access the interior of themotor housing 110. A user need simply remove the tray in order to accessthe interior of the housing.

Grease accumulated on the fans and within the motor housing, istherefore forced out of the range hood by air delivered by air hoses162, 12, 14, 16, 18, 26, and 28. The preferred embodiment thereforecovers 3 main areas: the fans, the upper to lower interior of the motorhousing and the lower surface of the motor housing. It is contemplated,however, that other embodiments could cover one or more of these areas.

Preferably, plates 8 will be made of metal and will be of similarthickness to the motor housing. However, it is also contemplated thatother solid substances such as plastic could be used. The plate can be avariety of shapes provided that it provides a surface upon which tomount the air dispensers and protects the air dispensers from cominginto contact with the fans. For example, the plate could be star-shaped,with an air hose and nozzle mounted at each but one point of the star,at which point all the air hoses will meet so as to exit the housing 110en masse. However, as discussed above, it is preferred that the plate becircular as this provides the least interference with the air flowwithin the chambers 2, 4 when the range hood 100 is in operation. Theplate need not be continuous, and in the preferred embodiment has gap 10which is dimensioned to allow the power cord 50 from motors 125 to fitwithin it. Alternatively, the plate could have a rounded trough,dimensioned to provide sufficient space for the motor power chord to fitwithin when the motor 125 and plate 8 are attached to the motor housing110. Similarly, while in the preferred embodiment the air hoses will beattached to the upper surface of the plate 8 by way of flexible metalloops welded to the plate (not shown), it is also contemplated thatother methods of connection could be used, such as glue, or plasticmolding.

An alternative embodiment is shown in FIGS. 4 and 5. Range hood 200 hasmotor housing 110 within hood body 202. In this embodiment fan 220 is ofthe squirrel cage type and is attached to motor 125. In order to removegrease from the fan 220, nozzle 260 is used. At one end nozzle 260 hastwin heads for greater dispersion of compressed air against the fan 220.One end of air hose 262 is attached to the other end of nozzle 260,while the other end of air hose 262 is attached to an air compressor.The remainder of the air dispensers of the cleaning assembly are similarto that described in relation to the preferred embodiment shown in FIGS.1-3.

Range hood 200 also has a different tray 240 and lower panel 108 design.In this embodiment, tray 240 has inner wall 244 and concentric outerwall 242. Inner wall 244 is proximate to, and defines, an opening. Outerwall 242 is distal from the opening in relation to the inner wall 244.Outer wall 242 is shaped and dimensioned to fit within gap 134 when tray240 is connected with housing 110 so that a portion of outer wall 142 isin abutment with wall 130. Preferably, the diameter of inner wall 244 issmaller than the diameter of lower fan edge 222. The tray 240 isdimensioned such that when connected with the motor housing 110, the topof inner wall 244 is just below the level of fan 220, thereby directingair into the housing 110 by way of the fan 220.

Nozzle 260 may be releasably or permanently attached to tray 240 suchthat when the tray is connected to motor housing 110, hose 260 may thenbe attached to nozzle 262. Connection means such as a clip 290 are usedto connect air hose 262 to one end of nozzle 260. It is contemplatedthat other methods of connection would be equally viable. Compressed airfrom the compressor is sent through air hose 262 and is dispersed bynozzle 260 against fan 220 thereby blowing any accumulated grease intothe interior of the motor housing 110.

In order to access the interior of the range hood, one must remove lowerpanel 208, which has integrated fan grill 238 to prevent insertion ofobjects into the fan 220.

A further alternative embodiment of a range hood 300 is shown in FIGS. 6and 7. Enclosed in hood body 302, motor housing 310 is compartmentalizedin a similar fashion to the housing 110 of the preferred embodiment.However, the lower surface 313 of motor housing 310 is shaped such thatgrease accumulated in the housing interior drains into tray 340. The airdispensers 12, 14, 16, 18 are the same as in the preferred embodimentand act to force condensate from the upper surface and down the sides tothe lower surface of the motor housing and finally into tray 340. Theforce generated by the air of air hoses 12, 14, 16 and 18 is sufficientto drive accumulated grease down the sides of the housing towards tray340. Accordingly, there is no need for an additional air hose/nozzle inthe side of the housing to drive the grease along the bottom as in thepreferred embodiment.

Tray 340 has outer wall 342, inner wall 344, separating wall 348, outertrough 346 and inner trough 345. Separating wall 348 acts to control airflow into the motor housing as is known in the art. Most condensatedrains into outer trough 346. However, a very small amount may draininto inner trough 345. Integrated nozzles 370, pass through outer wall342 such that they are facing in opposite directions. Air hoses 372connected to an air compressor may be releasably attached to nozzles370. Compressed air delivered through air hoses 372 is directed bynozzles 370 about the circumference of outer trough 346, thereby forcingany accumulated condensate towards drainage holes 380 and 382.Alternatively, a single nozzle having twin heads could be used such thatthe number of nozzles passing through the tray is reduced.

An integrated fan nozzle 360 passes through each of walls 342, 348 and344. Air hose 362 attached to an air compressor may be releasablyattached to the fan nozzle 362. Compressed air travelling through airhose 362 is directed by fan nozzle 360 against the fan 120 therebyforcing any accumulated grease into the interior of the motor housingwhere is then forced down to tray 340. As shown in FIG. 7, channel 395travels from inner trough 345 through wall 348, outer trough 346 to wall342 where it combines with drainage hole 380. Drainage hole 382 islocated on the opposite side of a partition wall 390, thereby allowinggrease forced around that side of the tray to drain out of the rangehood. Grease drains through drainage holes 380 and 382 to externalgrease cup 326.

To access the motor housing interior, first lower panel 308 withintegrated fan grill 338 must be removed from the remainder of the hoodbody 302. Using crips 290, hoses 362 and 372 are removed from nozzles360 and 370 respectively, before removing tray 340.

As is apparent from the three embodiments described above, the cleaningassembly of the present invention may be adapted for various range hooddesigns. The main elements of the system being a source of compressedair and air dispensers to direct the compressed air against greasecoated surfaces so as to force grease out of the range hood. Furtheralternative embodiments of the invention are contemplated by combiningdifferent fan types with different motor housing and grease traydesigns.

The cleaning assembly of the invention may be activated in one of twoways. First, the range hood may be adapted such that the aircompressor(s) of the cleaning assembly is automatically activated for aset period of time each time the range hood is shut off. The duration ofair compressor activity may be varied, however it preferably lasts forapproximately 15 seconds.

Alternatively, the air compressor of the cleaning assembly may beactivated manually. In this way, if the range hood is subjected toparticularly greasy vapour on a given day, the cleaning assembly may beactivated manually in order to ensure that sufficient air is blownthrough the system to drive out all the accumulated grease.

Typically only a very small amount of grease accumulates on a fan asmost is dispersed by means of the centripetal force of the rotating fan.However, any grease or liquid that remain on the fan will be blown tothe interior of the housing by compressed air as discussed with respectto the various embodiments above. The compressed air directed againstthe fan will cause the fan to turn due to the force exerted on the fanblades, thereby ensuring that each blade of the fan is struck bycompressed air in turn. The fan is prevented from spinning too rapidlyby the natural resistance of the motor 125. As a result of the greasebeing removed from the fan, very little grease accumulates in the trays140 and 240 and inner trough 345, and they need only be checked, andcleaned if necessary, during regular maintenance of the range hood andneed only have minimal depth.

It will be appreciated by those skilled in the art that the preferredand alternative embodiments have been described in some detail but thatcertain modifications may be practiced without departing from theprinciples of the invention.

1. A range hood including a motor housing having an interior defined byupper, lower and side surfaces containing at least one motor and atleast one fan and having at least one drain hole, said range hood alsoincluding a cleaning assembly comprising at least one source ofcompressed air located externally to said motor housing and a pluralityof air dispensers for delivering said compressed air to said interior todrive grease towards said at least one drain hole.
 2. A range hoodincluding a motor housing having an interior defined by upper, lower andside surfaces containing at least one motor and at least one fan, and atleast one grease tray releasably attachable to said motor housing, theor each grease tray comprising an opening, first, second and third traywalls extending around said opening, a first trough formed between thefirst and second tray walls, a second trough formed between the secondand third tray walls, and at least one drain hole, said range hood alsoincluding a cleaning assembly comprising at least one source ofcompressed air located externally to said motor housing, and a pluralityof air dispensers for delivering said compressed air to said interior todrive grease towards said at least one drain hole.
 3. A range hoodaccording to claim 2, wherein at least one of said plurality of airdispensers is fixed relative to said first, second and third tray walls.4. A range hood according to claim 3, wherein said at least one of saidplurality of air dispensers directs compressed air from said source ofcompressed air against said at least one fan.
 5. A range hood accordingto claim 2, wherein, in respect of the or each tray, at least one ofsaid plurality of air dispensers is fixed relative to the first traywall and directs compressed air from said source of compressed air intothe first trough.
 6. A range hood having a cleaning assembly comprising:a range hood body defining an enclosure, said range hood body having aremovable lower panel; a motor housing defining a further enclosure,said motor housing having an intake opening and a drainage hole andbeing mounted within said range hood body; a motor mounted within saidmotor housing enclosure; a fan releasably connected to said motor, saidfan being positioned within said motor housing enclosure; a source ofcompressed air located externally to said motor housing; and a pluralityof air dispensers for delivering said compressed air into said motorhousing enclosure to drive grease within the motor housing towards saiddrainage hole.
 7. The range hood of claim 6 further comprising a platereleasably attachable about said motor above said fan, a space beinglocated between said plate and said motor housing and above said plate.8. The range hood of claim 7 wherein a first one of said air dispensersis mounted to said plate in said space.
 9. The range hood of claim 8wherein said motor housing having an interior and said first one of saidair dispensers directing compressed air from said source of compressedair against the upper surface of said motor housing interior.
 10. Therange hood of claim 9 wherein a second one of said plurality of airdispensers being releasably attachable to the lower surface of saidmotor housing, said second one of said air dispensers directingcompressed air from said source of compressed air against said at leastone fan.
 11. The range hood of claim 10 wherein a third one of saidplurality of air dispensers being integral with the side of said motorhousing, said third one of said air dispensers being positioned withinsaid motor housing interior above a top side of said lower surface ofsaid motor housing, said third one of said air dispensers directingcompressed air from said source of compressed air along said top side ofsaid lower surface of said motor housing.
 12. The range hood of claim 6further comprising a grease tray releasably attachable to said motorhousing, said grease tray comprising an opening, first, second and thirdtray walls extending around said opening, a first trough formed betweensaid first and second tray walls, a second trough formed between saidsecond and third tray wall, and at least one drainage hole, and whereina first of said plurality of air dispensers is integral with said first,second and third tray walls and directs compressed air from said sourceof compressed air against said at least one fan.
 13. The range hood ofclaim 12 wherein a second one of said plurality of air dispensers isintegral with said first tray wall, said second air dispenser directingcompressed air from said source of compressed air into said firsttrough.
 14. The range hood of claim 13 wherein said motor housing havingan interior and a third one of said plurality of air dispensers beingadapted to direct compressed air from said source of compressed airagainst the upper surface of said motor housing interior.
 15. The rangehood of claim 6 wherein said motor housing having upper, lower and sidesurfaces defining said enclosure, said intake opening and drain holebeing defined in said lower surface, said intake opening being definedby a wall projecting from said lower surface into the interior of saidenclosure; and said range hood further comprising a tray releasablyconnectable to said intake opening, said tray comprising an opening,first and second tray walls extending around said opening, and a floorbetween said first and second tray walls.
 16. The range hood of claim 15wherein at least one of said plurality of air dispensers is releasablyattachable to said lower surface of said motor housing, directingcompressed air from said source of compressed air against said at leastone fan.
 17. The range hood of claim 16 further comprising a platereleasably attachable to said motor housing about said motor and abovean upper surface of said fan such that there is a space between saidplate and said motor housing.
 18. The range hood of claim 17 wherein afirst one of said plurality of said air dispensers is mounted to saidplate in said space.
 19. The range hood of claim 15 wherein at least oneof said plurality of air dispensers is integrally mounted in said sideof said motor housing, said at least one of said plurality of airdispensers being positioned within said motor housing interior abovesaid lower surface of said motor housing, and being adapted to directcompressed air from said source of compressed air against said top sideof said lower surface of said motor housing.
 20. The range hood of claim15 wherein at least one of said plurality of air dispensers isreleasably attachable to said tray, said at least on of said pluralityof air dispensers directing compressed air from said source ofcompressed air against said at least one fan when said tray isreleasably connected to said intake opening.